discover_weekly_diff

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full disclosure burden and delivers meaningful non-derivable traits: the cost profile '2-3 reads (+1 write only with save_after)' conveys side effects and near-read-only safety, and 'Resolves both playlists by exact name' discloses matching behavior that could cause failures. It stops short of a 5 because it doesn't describe what happens when the archive playlist is missing or name collisions occur.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences with zero filler: purpose and outputs first, then cost profile, then resolution behavior. Every sentence earns its place and the most decision-relevant information is front-loaded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 5-parameter tool with zero required parameters, a fully documented schema, and no output schema, the description supplies the conceptual model an agent needs: what is compared, what is reported, how playlists are resolved, the read/write cost, and output modes (via response_format). The only notable gap is edge-case behavior such as missing-archive handling, which would push this to a 5.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline of 3 applies. The description adds only marginal semantic value—clarifying that save_after is the write gate and archive_name is the resolved playlist—while the schema already documents every parameter with defaults, bounds, and enum choices.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names the exact comparison—this week's Discover Weekly versus the last archived copy—and enumerates the three outputs (what is new, what overlapped, which tracks are already liked). This specificity sets it apart from the many generic diff siblings (playlist_diff, diff_playlists, diff_since_snapshot) by being Discover Weekly–specific. The verb is implied via 'vs' but unmistakable.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage context is implied rather than stated: the archive_name parameter notes the archive is 'kept by save_discover_weekly,' signaling this tool runs after that sibling in a weekly workflow. However, there are no explicit when-to-use/when-not-to-use conditions or named alternatives, and the sibling list contains numerous similar diff/checkpoint tools with no routing guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.